The topic of this diploma thesis is about the fascination of mercenary soldiers. According to reams of sources, mercenary soldiers have already existed in the ancient world. Some authors discuss about what really is the oldest business of the world: Mercenary or prostitution? One thing can be said doubtless: Both have already existed before the implementation of money.Mercenary soldiers had their consumer boom during Emperor Maximilian I of Austria, at the turn of the centuries 15th to 16th. In front of all, during the 16th century the law of lansquenets develops quite fast. We can observe the codification, the development of the regiment bureaus and the advancement of the process flow. The zenith of the lansquenets ranges from the reforms of Emperor Maximilian I. of Austria to the end of the Thirty Years? War. Parallel to the end of this war, the age of lansquenets dies. Even if the law of lansquenets has developed that fast, at the end of the 17th and the 18th century, this development comes to a holdup. The introduction of the so-called ?conscription-system?, the French Revolution and the beginning of the compulsory military service, leads to more importance again of the mercenary soldier law. A second boom started with the beginning of the colonial era that led to a lack of mercenary soldiers in Europe.Authoritative and binding rules of international law concerning the problem of mercenary soldiers have been introduced at the beginning of the 20th century first. By decades, international organizations as well as governments and other institutions tried to fix binding rules and binding law to get this problem under control. A lot of resolutions by the Security Council as well as the General Assembly of the United Nations, conventions and rules of national law concern that problem but until nowadays, this problem is not terminally solved.